docs: def function_inclusion_filter_builder(func: Strings) -> NodePredicate:
      """Build a filter that only passes on nodes of the given function(s).
  
      :param func: A BEL Function or list/set/tuple of BEL functions
      """
      if isinstance(func, str):
          return _single_function_inclusion_filter_builder(func)
  
      elif isinstance(func, Iterable):
          return _collection_function_inclusion_builder(func)
  
      raise TypeError('Invalid type for argument: {}'.format(func))